Use the Action Replay go to pokemonaction replaycodes.com for the code.
no you have to get is from an action replay or go to a Pokemon event
Dialga
trade with Pokemon Platinum
You have to get oak's letter at on a special event.
You can't.
Action Replay.
You can get it from an event or trade.
Only through a Pokemon event
Only if you got the event.
definitely a Nintendo event
not sure
either by cheating or a wifi event (but wifi event expired)